Earth-boring drill



Feh. 5 1924.

H. W. FLETCHER EARTH BORING DRILL Filed Sept. 13, 1920 MW fZ[76H[/? INVENTOR.

BY SCI WW ATTORNEYS.

7 carrying large till Patented Feb. 5, 1924.

um'rso STATES PATENT OFFICE.

:: :uLD W. FLETCHER, OF HOUSTON, TEXAS, ASSIGNOB TO HUGHES TOOL COHPAN Y, OF HOUSTON, TEXAS, A CORPORATION OF TEXAS.

. EARTH-BORING- DRILL.

Applleetlonflled September 18, 1820. Serial No. 410,085.

To all whom it may concern."

Be it known that I, one W. Future, a citizen of the United States, residing at Houston, Harris County, Texas, have invented a certain new and useful Improve- -ment in Earth-Boring Drills, of which the followin is a full, clear, and exact description, sue. as willenable others skilled in the art to-which it' appertains to make and ltl use'the same.

- My invention relates to an imrovement in rotary earth boring drills an has particular application to roller drills adapted to cut in hard formation, such as rock, hard sd, etc, in the drilling of wells for oil, water, gas, etc.

In the drilling of such wells, it is customary to cut the strata, through which the drill progresses, by the rollin of toothed cutters on the bottom of the ho e, thus disintegrating the material, which is ground up and is carried upwardly away from the cutters in suspension by streams of flushin fluid pumped downwardly throu h the dri stem. The flushing fluid ordinar' y used is water quantities of mud in. suspension. This mud naturally contains quantities of sand and grit, and, in its passage downwardly through the channel in the head of the bit, so as to discharge upon the cutters, acts to wear away the walls of the chamel. Furthermore, in drills of this character, where the head of the bit is longitudinally divided, it has been customary to form the water channels by thecutting of grooves in the meeting faces of the separate arts of the head. In this construction, un ess the parts of said head fit very tightly together, flushing fluid may escape laterally, in small quantities, from the channel to the outside of the head. These small passages naturally are worn and it soon he pens that a material leakage occurs from t e channel laterally along the meeting faces of removable the split head.

An object of my invention is to rovide a drill of the \character set forth, a a water course therethrough, which, when worn, may be replaced.

Another object is to so form the chel for the flushing fluid that there will be no lateral escape for the fluid, as in the prev1ous types of split head bits.

. Another object is to rovide a drill havlng reaming rollers in t e sides of the head, these rollers being set in a diametrical recess through said head and a channel for the flushing fluid, which will conduct the fluid downwardly through said recess and discharge the same upon the lower cutters in the usual manner.

Another object is to rovide a means of conducting lubricant t ugh the longitudinally divided head and the central recess therein so as to allow no escape for the lubricant.

l have shown in the drawing a preferred embodiment of my invention, Fig. 1 being a central longitudinal section through the same on the line l+1 of Fig. 2; and Fig. 2 being a transverse section on the line 2'2 of Fig. 1. Like numerals of reference are applied to like parts in both the views.

lhe type of drill disclosed in the drawing is similar to that disclosed in the prior patent to Hughes, No. 1,174,57 5, issued March 7, 1916, and comprises a head 1 aproximately cylindrical in shape and havmg a reduced upper shank 2, threaded for attachment toa drill stem 3. At the extreme upper end the head is still further reduced in diameter'at 4 and threaded for attachment to a collar 5, having an upper nipple 6 for attachment to a lubricant container 7.

The head 1 is formed with a V-shaped slot 8 in the forward end thereof, on the flat faces of which are provided threaded stub shafts 9, upon which the bearings 10 of rotary movabl mounted. The head is longitudinallydivided into two parts along a central plane 12. These parts are maintained in registered position by means of transverse locking bolts 13, held against removal by means of cotter pins 14:, and also by the threading of the upper shank 2, within the drill stem 3. Lubricant is conducted to the bearings from the container 7, through a central duct or channel 14: in the nipple 6, and branching ducts leading from said frusto-conical cutters 11 are recentral channel downwardly through the collar 5, to an annular groove or recess 16 in the base of said collar, from which the lubricant is fed downwardly in an inclined direction through oil ducts 17, through a central recess 18, and from thence in an outwardly inclined-direction to discharge the lubricant through connecting ducts 19 in the cutter shafts 9, from which the lubricant is fed to the bearings 10, as shown.

Beaming rollers 20 are mounted in housings or pockets 21, formed by recesses cut n the contacting faces of the longitudinally divided head. These ockets are formed opposite each other and are connected by a diametrical opening or recess 18 through the head. This connecting opening 18 is formed in the head for purposes of construction, it being practically impossible in casting steel for the head to form a web between the opposite pockets 21-and also allow for a central water channel, to be later described. The reaming rollers 20 are mounted upon upright pins 22, set in the meeting faces of the head above and below the pockets 21. The upper and lower ends of the pins 22 are set in squared recesses 23 to prevent rotation of the pins, in an obvious manner. The flushing fluid is conducted downwardly through the head by means of a central removable water course 24, formedby means of a length of pipe or tubing 25 threaded at 26, at the upper end, for attachment to the collar 5. A plurality of inwardly inclined channels 27 allow entrance of the flushing water from within the drill stem to the upper endof the water course 25. This water course is mounted in central registering grooves in the meeting faces of the two parts of the head. Flushing fluid passing downwardly through this water course is discharged upon the upper edges of the cutters 11 and is adapted to clean the same of material adherin thereto and to wash the cuttings u war y outside of the drill stem to the sur ace.

The advantages of a central removable water course such as disclosed herein, are particly 1n theifact that it is removable when worn and allows no lateral escape of the fluid from the headof the bit. 7 It allows water to be discharged throu h the central passage or opening 18 connecting the reamer pockets without the liability of the dispersing of flushing fluid laterally against the reamin rollers.

The orming of removable lubricant ducts 17', which are driven downwardly through the head of the bit to a point well beyond the central opening 18, provides a continuous oil duct from which no lubricant can escape, and the channels may be readily bored in the head in an economical manner.

Having thus described my invention, what answer I claim as new and desire to protect by Letters Patent is:

1. In a rotary earth boring drill, the combination of a longitudinally divided head, cutters on the forward end thereof, reaming rollers mounted in a recess extending diametrically through said head, a removable water course mounted in grooves in the meeting faces of said divided head and extending longitudinally through said recess, and a collar at the upper end of said head having channels connecting with said removable water course.

2. In a rotary earth boring drill, the combination of a longitudinally divided head, cutters on the forward end thereof, reaming rollers mounted in a recess extending diametrically through said head, and a removable water course mounted in grooves in the meeting faces of said head and extending longitudinally through the said recess and said head in the manner described.

3. In a rotary earth boring drill, the combination of a longitudinally divided head, rolling cutters on the forward end thereof, a removable water course mounted in grooves in the meetin faces of said head, a collar at the upper end of said head having channels connect-in with said removable water course an a lubricator on said collar having lubricant ducts leading to an annular groove in the base thereof and tubes leadin from said groove through said head to said outters.

4. In a rotary earth boring drill, the combination of a head longitudinally divided into a plurality of parts, registering grooves in the contacting faces of said head, and a fremovable pipe extendin through said head and ttin with said grooves, and a collar constituting a lubricator attachment at the upper end of said head having channels for flushing fluid therein connecting with said central pipe above said head, in the said collar acting also to assist in holding the parts of the head together.

5. In a rotar earth boring drill, the combination of a li ead, cutters on the forward end of said head, reaming rollers mounted in pockets in the sides of said'head, said pockets being connected'by a central opening and a central removable pipe extending downwardly throu h said head and adapted to conduct the flusliing water throu h said opening and discharge the same at t e forward end of the bit.

6. In a rotary earth boring drill, a longitudinally divided-head, cutters onthe' forward end thereof, an enlarged passage in said head, a removable water-course mounted in the meeting faces of said head and making a-close fit therewith only at the upper and lower ends of said head and adapted manner described,

longitudinally to convey flushing fluid through said head nall through said head and said pockee to and. said enlarged passage in the manner decon uci; lubricant to the bearings of said N scribed. cutters.

7. in a rotary earth boring drill, a head, In testimony whereof, I hereunto afiix my 5 rotary cutters thereon, said head having a signature, this the 8th day of September,

diametrical pocket therethrough, a lubricant A. D. 1920. container on said head and removable ducts extending from said lubricator longitudi- WiFLETCHER. 

